1. Technical Field
The present disclosure relates to an optical device, and particularly, to a lens for forming asymmetric light field and an illumination device having the same.
2. Description of Related Art
Light emitting elements (LEDs) are extensively applied due to high brightness. LED illumination device usually provides a symmetrical light field with a circular cross-section. However, sometimes an asymmetric light field is required or preferred for specific illumination or power-saving applications. For example, it is preferred that a streetlamp illuminates on the road than on the space behind the streetlamp.
Therefore, it is desirable to provide an illumination device which can overcome the described limitations.